1. Field of the Invention
The present invention relates to a universal power supply system and more particularly to a power supply system for industrial computers or servers.
2. Description of the Related Art
Regular industrial computers or servers should be able to sustain long-time operation and therefore require operating power supplied from power supply systems with high power or redundant power. Because industrial computers or servers produced by computer manufacturers may have different power specifications, in response to such concern, manufacturers of regular power supply systems provide a modular power supply system. With reference to FIGS. 9 and 10, a conventional modular power system 50 has a housing 51, a backboard module 52, multiple AC-to-DC (AC/DC) power supply devices 53 and multiple board mounted DC power modules 54.
The housing 51 has a first opening and a second opening opposite to each other.
The backboard module 52 is mounted to the first opening of the housing 51, and has multiple DC power and communication interfaces 521 and a monitoring circuit 522. Each DC power and communication interface 521 has a DC power input/output (I/O) port 521a and a communication port 521b. The monitoring circuit 522 is electrically connected to each communication port 521b. The monitoring circuit has multiple enable terminals SEN1, SEN2, multiple current detection terminals IS1, IS2, and multiple critical current values and critical power values.
The AC/DC power supply devices 53 are mounted in the housing 51 through the second opening A DC power output terminal DC/OUT1, DC/OUT2 of each DC power supply device 53 is connected to the DC power I/O port 521a of a corresponding DC power and communication interface 521 and is connected to the monitoring circuit 522 of the backboard module 52 through a communication connection port (IIC1, IIC2).
The board mounted DC power modules 54 are mounted inside the housing 51 through the second opening. Each board mounted DC power module 54 has a terminal port, an enable terminal EN and a current output terminal ISENSE corresponding to the DC power and communication interface 521 of a corresponding backboard module 52 to acquire DC power outputted from a corresponding AC/DC power supply device 53, converts the DC power into a DC power with a specific voltage level, and outputs the converted DC power. The enable terminal EN and the current output terminal ISENSE are connected to the communication port 521b of the DC power and communication interface 521. The monitoring circuit 522 compares a current outputted from each board mounted DC power module 54 with a predetermined critical current value. If the output current is greater than the critical current value, the monitoring circuit 522 controls a corresponding enable terminal SENT, SEN2 to disable the over-current board mounted DC power module 54 so as to prevent the power system 50 from burning out due to the over-current situation.
The AC/DC power supply devices 53 mounted inside the housing 51 of the modular power supply system 50 may have an identical wattage or different wattages. According to a power supply demand, the backboard module 52 is collaborated with the board mounted DC power module 54 to output in series or in parallel a DC power supplied from the respective AC/DC power supply devices 53 and converted from the respective board mounted DC power module 54. Alternatively, the DC power of one of the board mounted DC power modules 54 may serve as backup power. Furthermore, the monitoring circuit 522 of the backboard module 52 monitors if the current outputted from each board mounted DC power module 54 is in an over-current status when compared with a corresponding critical current value. If positive, the monitoring circuit 522 controls to disable the over-current board mounted DC power module 54 for over-current protection (OCP). Besides, as the backboard module 52 further provides over-power protection (OPP), the monitoring circuit 522 allows that the wattages of two AC/DC power supply devices are both 500 W during a parallel output (current share) mode when the modular power supply system 50 supplies 500 W DC power, or allows that each AC/DC power supply device outputs a 250 W DC power. The monitoring circuit 522 basically sets up 500 W as a critical power value. Once one of the AC/DC power supply devices is faulty, the other AC/DC power supply device supplies 500 W DC power alone. Hence, when two AC/DC power supply devices have the same wattage in operation, the critical power value can be fixed.
Because of a standardized design, when the modular power supply system 50 is repaired or the modular power supply system 50 with various wattages is built, the AC/DC power supply devices with different wattages satisfy the requirement and can be all mounted inside the housing. Hence, when the modular power supply system 50 is repaired, if one of the AC/DC power supply devices with 500 W is replaced by an 875 W AC/DC power supply device, the parallel output mode is not activated as the backboard module detects that the two AC/DC power supply devices supply power with different wattages (500 W, 875 W). Instead, one of the AC/DC power supply devices is enabled as a master while the other AC/DC power supply device functions as a slave. The master supplies power while the slave does not but only serves as a backup power source. If the 875 W AC/DC power supply device is selected as the master and the critical power value is still 500 W, damage arising from the over-power condition is inevitable.
As the AC/DC power supply devices and the board mounted DC power modules used by the modular power supply system are modularly designed, power supply manufacturers no longer need to redesign the corresponding circuits or circuit boards. All it needs is just to customize the backboard module based on the demands of different power wattages or types of power outputs.
However, the power wattage or DC power specifications of the modular AC/DC power supply devices and the board mounted DC power modules used by the power supply manufacturers can be hardly identified from the appearance. As a consequence, the modular power supply system assembled by the power supply manufacturers is thus prone to errors, such as a board mounted DC power module plugged in a wrong DC power I/O port of the backboard module. Additionally, the modular power supply system currently still replies on a customized backboard module preventing the production efficiency from being effectively increased.